The present invention relates to an improved barbecue grill having a means for retarding an excessive flame which may be produced during the cooking process, incorporating a means for sensing light from the flame and responding to it with the distribution of a fluid fire suppressant to retard the excessive flame. Excessive flames are typically those which create either a safety or a cooking hazard. They can sensed in the planar region below and in proximity to the horizontal grill which supports food being barbecued.
Various modes of fire suppression, including the use of various water supply devices, used in combination with barbecue grills are known in the prior art. In 1911, U.S. Pat. No. 1,006,210 was issued to Held for a dust allaying attachment for furnaces which distributes water from a circular configuration. The device taught relates to dust rather than flame suppression.
In 1968, U.S. Pat. No. 3,362,586 was issued to Dedoes for a barbecue fan fire quenching accessory which physically resembles a portable flash light comprising a fan on one end and a water dispensing nozzle on the other. The accessory taught is manually operated and requires the user to be in proximity to the flames during operation.
In 1973, U.S. Pat. No. 3,756,140 was issued to Kolivas for a barbecue pit incorporating a built-in flame extinguisher system for extinguishing flames which flare up as a result of hot grease dripping upon the hot coals and the like. In FIG. 3 of the drawing, a flame extinguisher (175) within the barbecue pit is shown. The flame extinguisher includes a conduit having running water therein and terminating at a strategic point within the pit. The protruding end of the conduit is suitable fitted with a nozzle which discharges a fan-shaped spray therefrom. The disadvantage of this device is that it is adapted only to permanently fixed barbecue pits such as the masonry unit shown in the drawing and it only operates manually.
Additionally, a water-cooled safety grate for a barbecue grill is disclosed in U.S. Pat. No. 4,632,089, and in 1987 a kit for extinguishing charcoal fires by submerging the coals in a container of water was revealed in U.S. Pat. No. 4,655,294.
Moreover, two patents dealing with fire retardation are shown in U.S. Pat. Nos. 4,630,593 and 4,281,633. The first employs a fire retardant screen, placed between the charcoal and the cooking fare; and the latter provides an air modulated charcoal cooking container, which can be positioned to snuff out flames. Both inventions require manual operation from a location in proximity to the flames.
In connection with fire detection systems, the use of a flame detector is well known. U.S. Pat. No. 3,299,416 issued to Koppel in 1967 discloses a circuit for an ultra-violet self-checking flame detector. U.S. Pat. No. 3,825,397 issued to Johansson et al. in 1974 reveals the novel use of fiber optics means to transmit light from a burner flame of a car heater further employing a light detector comprising a photo diode, a photocell, a photo resistance or the like.
Flame sensors have been employed in industrial boilers as is shown in U.S. Pat. Nos. 4,039,844, 4,435,149, and 5,026,272. Additionally, tubular optical waive guides are taught in U.S. Pat. No. 4,855,718.
The disadvantages of the foregoing prior art relate to cost and complexity and the disadvantages in having to depend on a powerful power source.